AMD FX-6100 vs. FX-4170

Hi i'm finalizing a gaming desktop and i'm on a tight budget so want to get the best specs for my money.
I originally had settled on the FX-6100, but was looking at various benchmarks and many produced better results with the 4170. I know the 4170 is clocked higher, but has only 4 cores, so my question; which is better?
It will be running alongside a Radeon HD 6850 on the Asus M5a97 motherboard, and would play games such as Battlefield and COD.
Any idea's would also be grateful if you think there is a better Graphics Card or Motherboard for less or the same money!
Many thanks in advance!
Stuart